[QE-users] Convergence problem in vc-relax

[Ali Jaberi]

Hi,

I am trying to relax the structure for Li(Ni1/3Mn1/3Co1/3)O2. I could relax the structure with VASP but not with Quantum ESPRESSO. I have tried changing so many parameters but could not get any result so end up posting my problem here.

Here is my input file:

-----------------------------------------------------------------------------------------
&control
    calculation='vc-relax'
    nstep = 500,
    restart_mode = 'from_scratch' ,
    pseudo_dir = '....' ,
    outdir = './outdir'
    prefix = 'NMC',
    verbosity ='high' ,
    tprnfor = .true.
    etot_conv_thr= 1.0D-3
    forc_conv_thr = 1.0D-2
/

&system
    ibrav = 0,
    nat =36,
    ntyp =5,
    ecutwfc = 34 ,
    ecutrho = 380,
    occupations ='smearing',
    smearing='mv',
    degauss=0.001,
    nspin = 2,
    starting_magnetization(2)=0.7,
    starting_magnetization(3)=0.7,
    starting_magnetization(4)=0.7,
    lda_plus_u = .true.
    Hubbard_U(2)=4.84,
    Hubbard_U(3)=5.0,
    Hubbard_U(4)=5.96,
/

&electrons
    electron_maxstep = 700
    conv_thr = 1.0d-4,
    mixing_beta = 0.3,
    diagonalization = 'david',
/

&IONS
    ion_dynamics      = "bfgs",
/

&CELL
   cell_dynamics = 'bfgs'
   press_conv_thr = 0.9
/

ATOMIC_SPECIES
Li   6.940  Li.pbe-sl-rrkjus_psl.1.0.0.UPF
Mn  54.938  Mn.pbe-spn-rrkjus_psl.0.3.1.UPF
Co  58.933  Co.pbe-spn-rrkjus_psl.0.3.1.UPF
Ni  58.693  Ni.pbe-spn-rrkjus_psl.1.0.0.UPF
O   15.999  O.pbe-n-rrkjus_psl.1.0.0.UPF

CELL_PARAMETERS angstrom
4.92404724        0.00000000        0.00000000
-2.46202362        4.26435000        0.00000000
0.00000000        0.00000000       14.14560000

ATOMIC_POSITIONS angstrom
Co       -0.81985389        4.26292856       11.78328480
Co        0.82231591        1.42144999        2.34816960
Co        2.46202362        4.26435000        7.07280000
Li        0.00000000        0.00000000        0.00000000
Li       -0.81985389        4.26292856        4.71048480
Li        0.82231591        1.42144999        9.42096960
Li       -0.00000003        2.84290001        0.00000000
Li        1.64216978        2.84147854        4.71048480
Li        3.28433951        0.00000000        9.42096960
Li        2.46202364        1.42144999        0.00000000
Li       -0.81985387        1.42002855        4.71048480
Li       -1.63970776        2.84290001        9.42096960
Mn       -0.00000003        2.84290001        7.07280000
Mn        1.64216978        2.84147854       11.78328480
Mn        3.28433951        0.00000000        2.34816960
Ni        2.46202364        1.42144999        7.07280000
Ni       -0.81985387        1.42002855       11.78328480
Ni       -1.63970776        2.84290001        2.34816960
O         0.00000000        0.00000000        3.38910187
O         0.00000000        0.00000000       10.75649813
O        -0.81985389        4.26292856        8.09958667
O        -0.81985389        4.26292856        1.32138293
O         0.82231591        1.42144999       12.81007147
O         0.82231591        1.42144999        6.03186773
O        -0.00000003        2.84290001        3.38910187
O        -0.00000003        2.84290001       10.75649813
O         1.64216978        2.84147854        8.09958667
O         1.64216978        2.84147854        1.32138293
O         3.28433951        0.00000000       12.81007147
O         3.28433951        0.00000000        6.03186773
O         2.46202364        1.42144999        3.38910187
O         2.46202364        1.42144999       10.75649813
O        -0.81985387        1.42002855        8.09958667
O        -0.81985387        1.42002855        1.32138293
O        -1.63970776        2.84290001       12.81007147
O        -1.63970776        2.84290001        6.03186773

K_POINTS automatic
4 4 4 0 0 0
-----------------------------------------------------------------------------------------

Ther pressures I got for this relaxation are very high at each step!!!


          total   stress  (Ry/bohr**3)                   (kbar)     P=   -23972.31

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -26659.21

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24871.74

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24165.07

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24040.51

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -23928.12

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -23974.47

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24023.37

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24016.41

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24102.96

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24097.08

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24080.78

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -26559.80

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24814.82

          total   stress  (Ry/bohr**3)                   (kbar)     P=   -24024.82

This is exactly the structure VASP could converge so there should be a problem in the parameters or the algorithm. I really appreciate it if anyone could help me with this.

Best.
Ali Jaberi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20220712/fe2e2091/attachment.html>